JTAG interface device of mobile terminal and method thereof

ABSTRACT

A JTAG interface device capable of effectively debugging a mobile terminal by interfacing the mobile terminal with a JTAG emulator without an additional interface unit by allocating test pins of the JTAG emulator to some pins of a receptacle and then electrically connecting the test pins to the pins, and a method thereof. Accordingly, an operation for debugging the mobile terminal can be easily and effectively performed.

CROSS-REFERENCE TO RELATED APPLICATIONS

Pursuant to 35 U.S.C. § 119(a), this application claims the benefit ofearlier filing date and right of priority to Korean Application No.70549/2004 filed Sep. 3, 2004, the contents of which are herebyincorporated by reference herein in its entirety.

1. Field of the Invention

The present invention relates to a mobile terminal, and moreparticularly, to a joint test action group (JTAG) interface device usinga receptacle and a method thereof.

2. Background of the Invention

As communication techniques develop rapidly and users desire morefunctions, a mobile communication terminal (hereinafter, a mobileterminal) provides not only voice information but also text information(such as a stock data, weather, and real time news) and multimediaservices multimedia services (such as games and videos.)

However, in order to provide the above services, the number ofcomponents and circuits mounted in the mobile terminal has increased,and thereby increasing the time and cost to test for errors of thecomponents and the circuits. To address the problem of testing anincreased number of components and circuits, the Joint Test Action Group(JTAG) has developed a boundary-scan testing standard that has beenwidely adopted. The standard has been published by the IEEE as IEEE Std.1149.1, and is incorporated herein by reference.

Boundary testing defines a bus structure for testing internal componentsand circuits. Generally, an exclusive emulator for debugging and testinghardware is provided for testing component and circuit malfunctions.Presently, a JTAG type emulator is being used for this purpose. The JTAGtype emulator is an emulator for debugging hardware by mountingstandardized logic and test pins for testing a large-scale integratedcircuit (LSI) such as a complex programmable logic device (CPLD).

The JTAG type emulator interface requires an additional device such as aflexible printed circuit board (FPCB), and basically the emulatorinterface comprises five test signals: a test reset (TRST), test dataout (TDO), a test clock (TCK), a test mode select (TMS), and a test datain (TDI). The test signals are directly connected to an FPCB, whichfurther connect to components or circuits. A mobile station mode (MSM)controller tests for hardware or connection states.

However, to test circuits and components using the conventional JTAGemulator, a separate space for a JTAG interface is required, but spaceis a limiting factor in mobile terminal design. Also, the physicalconfiguration for a JTAG interface is different for each mobile terminaldesign with little standardization. Accordingly, each mobile terminalhas to be provided with an additional device for the JTAG interface suchas an FPCB.

SUMMARY OF THE INVENTION

Therefore, an object of the present invention is to provide a JTAGinterface device for interfacing a mobile terminal and a JTAG unit, anda method thereof.

Another object of the present invention is to provide a JTAG interfacedevice for interfacing a mobile terminal and a JTAG unit without anadditional interface unit, and a method thereof.

To achieve these and other objectives and in accordance with the purposeof the present invention, as embodied and broadly described herein,there is provided a JTAG interface device comprising: a mobile terminal;a JTAG emulator for debugging the mobile terminal; and a receptaclehaving a plurality of pins corresponding to test pins of the JTAGemulator, for directly interfacing the mobile terminal and the JTAGemulator. Preferably, the receptacle test pins are connected to thefollowing signals present in the mobile terminal: data set ready (DSR),on switch (ON_SW), pulse code modulation clock (PCM_CLK), PCMsynchronization (PCM_SYNC), and audio out signal (AUDIO_OUT).Preferably, the test pins are included in a single receptacle.

To achieve these and other advantages and in accordance with the purposeof the present invention, as embodied and broadly described herein,there is also provided a JTAG interfacing method of a mobile terminalcomprising: allocating test pins of a JTAG emulator to pins of areceptacle on a one-to-one basis; and directly connecting the allocatedtest pins to each pin of the receptacle thereby debugging a mobileterminal.

The foregoing and other objects, features, aspects and advantages of thepresent invention will become more apparent from the following detaileddescription of the present invention when taken in conjunction with theaccompanying drawings.

BRIEF DESCRIPTION OF THE DRAWINGS

The accompanying drawings, which are included to provide a furtherunderstanding of the invention and are incorporated in and constitute apart of this specification, illustrate embodiments of the invention andtogether with the description serve to explain the principles of theinvention.

In the drawings:

FIG. 1 is a view showing a JTAG interface device of a mobile terminalaccording to a preferred embodiment of the present invention; and

FIG. 2 is a view showing a connection state between pins of a receptacleand test pins of a JTAG emulator in FIG. 1.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

Reference will now be made in detail to the preferred embodiments of thepresent invention, examples of which are illustrated in the accompanyingdrawings.

The present invention provides a JTAG interface device for interfacing amobile terminal and a JTAG emulator by using a 24-pin receptacle. In thepresent invention, JTAG emulator test signals are allocated to specificpins of a 24-pin plug. The JTAG emulator plug is directly connectable tothe mobile terminal receptacle, thereby facilitating the debugging ofcomponents and circuits of a mobile terminal.

FIG. 1 shows a JTAG interface device of a mobile terminal according toan embodiment of the present invention, wherein a JTAG interfacecomprises a mobile terminal 100, a JTAG emulator 120 for debuggingcomponents or circuits of the mobile terminal 100, and a receptacle 110for directly interfacing the mobile terminal 100 and the JTAG emulator120.

The mobile terminal 100 has certain test signals connected to pins ofreceptacle 100. The receptacle pins are connected to the following testsignals present in the mobile terminal: data set ready (DSR), on switch(ON_SW), pulse code modulation clock (PCM_CLK), PCM synchronization(PCM_SYNC), and audio out signal (AUDIO_OUT).

The JTAG emulator 120 is provided with five test signals: a test reset(TRST), test data out (TDO), a test clock (TCK), a test mode select(TMS), and a test data in (TDI). The TRST is an initial signal for atest, the TDO is a data output signal, the TCK is a clock signal for atest, the TMS is a mode selection signal for a test, and the TDI isinput data.

The mobile terminal 100 test signals are connected to the JTAG emulator120 test signals through receptacle 110 as follows: PCM_CLK to the TCK,PCM_SYNC to TMS, AUDIO_OUT to TDI, DSR to TRST, and ON_SW to TDO.Preferably, the TRST signal, the TDO signal, the TCK signal, the TMSsignal and the TDI signal are included in one plug so as to be easilyconnectable to the receptacle. Preferably, the JTAG emulator 120includes all the five test pins so that each test pin of the JTAGemulator 120 can be electrically connected to the corresponding pin ofreceptacle 110.

The receptacle 110 is composed of 24 pins generally provided to a mobileterminal. Some pins of the receptacle 110 are allocated to the testsignals TRST, TDO, TCK, TMS, and TDI of the JTAG emulator 120. That is,the TDI signal which is a pull up input signal is connected to the AUDIOOUT (bi-directional pull up) signal having the same characteristic, theTMS signal having a high impedance output pin is connected to the PCMSYNC (bi-directional pull down) signal, and the TCK signal, which is apull up input pin, is connected to the PCM_CLK signal.

When certain pins of the receptacle 100 are connected to the test pinsof the JTAG emulator 120, interferences between the signals and theoperation of the mobile terminal 100 have to be considered. For example,since the DSR signal is scarcely used at the time of a datacommunication, DSR is connected to the TRST signal. Also, the ON_SWsignal used to detect an input of an external power is connected to theTDO signal.

FIG. 2 shows connections between the receptacle 110 signals and the JTAGemulator 120 test signals. As some signals of the receptacle 110 areallocated to the JTAG emulator 120 test signals, the mobile terminal canbe interfaced with the JTAG emulator 120 through the receptacle 110without an additional interface unit.

The JTAG interface device of a mobile terminal according to oneembodiment of the present invention will be explained in more detailwith reference to the attached drawings.

In the present invention, the third, sixth, eighth, ninth, and eleventhpins of the receptacle 110 are allocated to the test pins of the JTAGemulator 120. Accordingly, it is also possible to allocate other pins ofthe receptacle to the test signals of the JTAG emulator within a rangeof minimizing interference between each pin.

The JTAG signals of the JTAG emulator 120 (TRST, TDO, TCK, TMS and TDI)are allocated to specific pins of the 24-pin receptacle 110. Then, aplug of the JTAG emulator 120 is directly inserted into the receptacle110 to which each JTAG signal is allocated, thereby connecting the JTAGemulator to the mobile terminal. Accordingly, the TRST signal of theJTAG emulator 120 is the third pin of the receptacle 110, the TDO signalis the sixth pin, the TCK signal is the eighth pin, the TSM signal isthe ninth pin, and the TDI signal is the eleventh pin.

That is, the JTAG emulator 120 transmits each test signal to the mobileterminal 100 through the pins of the receptacle 110 to control acontroller of the mobile terminal 100 such as a mobile station mode(MSM). Accordingly, a debugging operation for testing components or aconnection state of the mobile terminal 100 is performed.

As described above in the present invention, the test pins of the JTAGemulator 120 are allocated to some pins of the receptacle 110 providedat the mobile terminal 100, and then are electrically connected to thethe mobile terminal 100 test signals, thereby interfacing the mobileterminal 100 to the JTAG emulator 120 without an additional interfaceunit. Especially, in the present invention, the mobile terminal 100 isdirectly interfaced with the JTAG emulator 120 through the receptacle110 without an additional interface unit, thereby reducing a debuggingcost, minimizing space in the mobile terminal, and solving a problemcaused as various components are mounted in the mobile terminal.

Also, in the present invention, it is convenient to debug components ora connection state of the mobile terminal, and thereby operationalefficiency can be enhanced.

As the present invention may be embodied in several forms withoutdeparting from the spirit or essential characteristics thereof, itshould also be understood that the above-described embodiments are notlimited by any of the details of the foregoing description, unlessotherwise specified, but rather should be construed broadly within itsspirit and scope as defined in the appended claims, and therefore allchanges and modifications that fall within the metes and bounds of theclaims, or equivalence of such metes and bounds are therefore intendedto be embraced by the appended claims.

1. A JTAG testing system for a mobile terminal, the system comprising: aJTAG unit having a plug with a plurality of test pins for debugging themobile terminal; and a receptacle mounted in the mobile terminal, havinga plurality of pins corresponding to test pins of the JTAG unit fordirectly interfacing the mobile terminal with the JTAG unit.
 2. Thesystem of claim 1, wherein the JTAG unit is a JTAG emulator.
 3. Thesystem of claim 1, wherein each of the plurality of pins of thereceptacle is connected to each of the plurality of test pins of theJTAG unit plug.
 4. The system of claim 3, wherein the JTAG emulatorfurther comprises a test clock signal (TCK), a test mode select signal(TMS), and a test data in signal (TDI), test reset signal (TRST), and atest data out signal (TDO), and wherein each of the signals is connectedto one of the plurality of test pins.
 5. The system of claim 3, whereinthe mobile terminal receptacle further comprises a pulse code modulationsignal (PCM_CLK), a synchronization signal (PCM_SYNC), an audio outsignal (AUDIO_OUT), a data set ready signal (DSR), and a power on signal(ON_SW), and wherein each of the signals is connected to one of theplurality of pins.
 6. The system of claim 3, wherein the TCK, TMS, TDI,TRST, and TDO signals are respectively connected with the PCM_CLK,PCM_SYNC, AUDIO_OUT, DSR, and the ON_SW signals.
 7. The system of claim3, wherein the TCK, TMS, TDI, TRST, and TDO signals are included in oneplug.
 8. The system of claim 3, wherein an existing receptacle of themobile terminal is adapted to accommodate the JTAG unit plug.
 9. Thesystem of claim 8, wherein at least one of the plurality of pins of theexisting receptacle that is connected to one of the plurality of testpins of the JTAG unit plug is used for a communication function of themobile terminal.
 10. A method of interfacing a JTAG unit to a mobileterminal for debugging the mobile terminal through the JTAG unit, themethod comprising: allocating a plurality of test pins of a plug of theJTAG unit to a plurality of pins of a mobile terminal receptacle;connecting the each of the plurality of test pins of the JTAG unit plugto each of the plurality of pins of the mobile terminal receptacle; andperforming debugging of the mobile terminal.
 11. The method of claim 10,wherein the JTAG unit further comprises a test clock signal (TCK), atest mode select signal (TMS), and a test data in signal (TDI), testreset signal (TRST), and a test data out signal (TDO), and wherein eachof the signals is connected to one of the plurality of test pins of theJTAG unit plug.
 12. The method of claim 11, wherein the plurality oftest pins is included in one plug.
 13. The device of claim 10, whereinthe mobile terminal receptacle further comprises a pulse code modulationsignal (PCM_CLK), a synchronization signal (PCM_SYNC), an audio outsignal (AUDIO_OUT), a data set ready signal (DSR), and a power on signal(ON_SW), and wherein each of the signals is connected to one of theplurality of pins of the mobile terminal receptacle.
 14. A method ofinterfacing a JTAG unit to a mobile terminal for debugging the mobileterminal through the JTAG unit, the method comprising: allocating aplurality of test pins of a plug of the JTAG unit to a plurality of pinsof an existing mobile terminal receptacle; connecting the each of theplurality of test pins of the JTAG unit plug to each of the plurality ofpins of the mobile terminal receptacle; and performing debugging of themobile terminal.
 15. The method of claim 14, wherein the existing mobileterminal receptacle is adapted to accommodate the plurality of pinscorresponding to the test pins of the JTAG unit.
 16. The method of claim15, wherein at least one of the plurality of pins of the existing mobileterminal receptacle that is connected to one of the plurality of testpins of the JTAG unit is used for a communication function of the mobileterminal.
 17. A method of interfacing a JTAG unit to a mobile terminalfor debugging the mobile terminal through the JTAG unit, the methodcomprising: adapting an existing mobile terminal receptacle toaccommodate a plug of the JTAG unit having a plurality of test pins;allocating the plurality of test pins of the JTAG unit plug to aplurality of pins of the existing mobile terminal receptacle; connectingthe each of the plurality of test pins of the JTAG unit plug to each ofthe plurality of pins of the mobile terminal receptacle; and performingdebugging of the mobile terminal, wherein at least one of the pluralityof pins of the existing mobile terminal receptacle that is connected toone of the plurality of test pins of the JTAG unit is used for acommunication function of the mobile terminal.